Backpack frame

ABSTRACT

A backpack having a forked frame with curved flat members that are shaped to conform to the curvature of a wearer&#39;s back. The flat members are connected together torsionally by a handle portion that allows each flat member to shift relative to the other to accommodate weight shifts in the backpack load. The forked frame is a single-piece structure that is preferably made of carbon fiber. Although the frame is external relative to the pack, the flat construction of the frame allows it to mate with the pack in a way such that the frame is integrated with the inner sidewall of the pack.

TECHNICAL FIELD

The present invention relates to backpacks, and more particularly, to backpacks having flexible frames.

BACKGROUND OF THE INVENTION

Conventional backpacks typically have a rigid tubular metal frame that is external of the pack or an internal frame. Either way, the frame supports the load within the pack and distributes the load across the wearer's hips, shoulders, and back. The invention disclosed here is a new frame design that provides a different way of supporting backpack contents and distributing the weight carried by the pack.

SUMMARY OF THE INVENTION

The invention is a backpack having a forked frame made of curved flat members that are shaped to approximately conform to and press against the curvature of a wearer's back. For the purpose of visualizing what is meant by “curved flat member,” one may liken the shape of these members somewhat to the shape of a steel leaf spring used in the automotive industry. In other words, the curved flat members used in the present invention are dimensionally long and wide, relative to their thickness, and can elastically bend or flex because of their relatively thin thickness. A handle portion of the frame connects the flat members together at the frame's top. The handle portion, as a connecting piece, enables the flat members to be torsionally flexible relative to each other. This flexibility accommodates weight shifts in the load carried by the backpack. The handle portion also allows the backpack to be carried like a suitcase when it is not being worn.

The handle portion and the flat members are integrally formed together from a single piece of material—preferably, carbon fiber. The lower portions of the flat members flare outwardly with respect to the portions of the flat members that are connected to the handle portion for providing support in the lumbar region of the back. There is a scapular pad connected to the flat members, near the handle portion, and a pair of lumbar pads connected, one each, to the outwardly flared portions of the flat members for cushioning effect.

In preferred form, the frame is external of the pack. However, its flat construction also “flatly” integrates the frame with the inside surface of the pack or packsack, i.e., the surface that rides on or against the wearer's back. While loads in the pack will cause them to flex along their length, and relative to each other, the curvature of the flat members, combined with their relative stiffness, serves to mold the inside surface of the packsack to the curvature of the wearer's back.

The backpack has shoulder straps that are conventional in nature, with the exception that each strap has an elastic section that permits the strap to stretch or extend when the backpack is worn. A separate strap or webbing spans the region of each shoulder strap where the elastic section is located. The separate strap is essentially non-elastic and has opposite ends connected to the shoulder strap outside and on opposite sides of the elastic section such that the length of the non-elastic strap is greater than the length of the elastic section when it is in a non-stretched condition (i.e., when the backpack is not being worn). When the backpack is placed on the wearer's back, the weight in the pack pulls against the straps and stretches the elastic section in each one—the reach of the elastic stretch is limited by the non-elastic strap.

The handle portion of the frame extends above the pack sack and curves aft relative to the wearer. This feature makes it easy to handle the backpack in certain situations when it isn't worn because it allows the backpack to be carried like a suitcase or briefcase.

The features of the invention as described above will become better understood upon review of the following description, which is to be taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference numerals and letters refer to like parts throughout the various views, unless indicated otherwise, and wherein:

FIG. 1 is a pictorial view of a backpack and backpack frame constructed in accordance with a preferred embodiment of the invention;

FIG. 2 is a pictorial view of the backpack frame;

FIG. 3 is a top view of the frame shown in FIG. 2;

FIG. 4 is a front view of the frame shown in FIG. 2;

FIG. 5 is a bottom view of the frame shown in FIG. 2;

FIG. 6 is a side view of the frame shown in FIG. 2;

FIG. 7 is a back view of the frame shown in FIG. 2; and

FIG. 8 is another pictorial view of the backpack shown in FIG. 1, but is taken from an angle looking at the back side of the backpack.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, and first to FIG. 1, shown generally at 10 is a backpack constructed in accordance with the invention summarized above. The backpack has a forked frame, indicated generally at 12. The frame has two curved flat members 14, 16 that are connected together by a handle portion 17. Referring now to FIG. 7, which is a back view of the frame 10 disconnected from the pack or packsack 40, the lower portions of the flat members 14, 16 flare outwardly as indicated at 18, 20, respectively.

As is best seen in FIG. 2, the lower-most region of the outwardly flaring parts or frame regions 18, 20 are lumbar-supporting areas or portions, indicated at 22, 24, respectively. Attached to these areas are two lumbar pads 26, 28. Similarly, a scapular pad 30 is connected to the flat members 14, 16 near the handle portion 18. The connection of the pads 26, 28, 30 to the frame 12 can be done in different ways. In the embodiment illustrated here, the connection is made by the pin and bolt arrangements 32, 34 for the lumbar pads and a pin and flange arrangement 36, 38 for the scapular pad 30.

The frame 12 is connected to the pack or packsack 40 by a series of pins or rivets that are located throughout various openings 42 in the frame 12. Like most conventional backpacks, the backpack 10 has a pair of shoulder straps 44, 46 and waist belt 48. In this particular instance, however, each shoulder strap 44, 46 has an elastic or elasticized section 50, 52 that stretches relative to the material that is used to make up other parts of each shoulder strap. Also, attached to each shoulder strap is a separate, substantially non-elastic strap 54, 56.

These separate nonelastic straps 54, 56 have a length that is greater than the length of the elastic sections 50, 52 of the shoulder straps when they are not stretched, which is the case when the backpack is not worn, as reflected in FIGS. 1 and 8. The opposite ends 58, 60 of each non-elastic strap are connected to each shoulder strap outside and on opposite sides of each elastic section. FIG. 8 is the best illustration of this arrangement. However, when the backpack 10 is placed on a wearer's back, the weight in the pack 40 puts the shoulder straps 44, 46 in tension and stretches the elastic sections 50, 52 until they stretch to the point where non-elastic straps 54, 56 take up the tension and prevent further stretching.

The materials used to make the elasticized sections 50, 52 and non-elastic straps 54, 56 are conventional elastic and nonelastic materials. The backpack frame 12 can be made from different materials, so long as they provide the structural shape described above. However, carbon fiber is the preferred material because of the way it can be molded to make a single integrated frame (as shown at 12 in FIG. 2, for example) and because of its attractive appearance. It is believed that a carbon fiber frame of the type described above is unique in the construction of backpacks or backpack frames.

The handle portion 17 of the frame 12 both connects and allows the flat members 14, 16 to torsionally flex relative to each other—which serves to distribute weight as the wearer walks or engages in other physical activities. Except for the torsional flex between members 14, 16, the frame is otherwise relatively rigid, with the understanding that the thin thickness coupled with the flat-sided construction of members 14, 16 does allow them to bend elastically forward and backward along with the torsional movement that one might have relative to the other. Dimensionally, in the backpack 10 illustrated here, the length of the curved flat members 14, 16 from handle portion 17 to scapular regions 22, 24 is approximately 18 inches. The width of the flat members 14, 16 near the scapular pad 30 is approximately 2.25 inches. They are about 0.125 inches thick. It is to be understood that these dimensions are examples only and will vary for different kinds of backpacks. The backpack 10 illustrated here is a size that is typically worn by students, although it could be used for day hikes as well. It may be possible to enlarge the dimensions of the frame for use in a backpack of the type used for overnight hiking or expeditions, although that has not been tried in a prototype, as of yet.

While openings 42 are provided in the frame 18 for using pins or rivets to connect the frame to the packsack 40, the mode of connection can be done in different ways. The frame can be permanently attached to the pack 40 or removable attachments (not shown) would provide a means for using the same frame for other types of packs or bag arrangements connected to the frame. As described above, the frame's handle portion 17 extends above the pack 40 so that it is easy to grip as an integrated part of the frame. It is curved aft, as is best seen at 62 in FIG. 6, for the purpose of making it easier to grip and/or carry the pack 10 by hand like a suitcase.

The lumbar and scapular pads 26, 28, 30 can also be connected to the frame in different ways and they can be adjusted to alter the way weight is distributed and/or to improve comfort. The scapular pad 30 in particular can be adjusted in height because the frame 12 has a plurality of pin openings 64 (see FIG. 2) that allow the pad 30 to be moved upwardly or downwardly relative to the frame. This adjustment is made depending on the height of the wearer.

While the wearer is not illustrated in the drawings, it is easy to see that the curvature of the frame's flat members 14, 16 allow the frame to follow the shape of the wearer's back so that the frame causes the pack 40 to conform to and press against the back. In this respect, the frame pulls the inner surface 66 of the pack 40 against the wearer's back in a comfortable fashion. The thin thickness of the frame 12 allows it to be integrated with the inner surface 66 of the pack. While it is described and illustrated here as an “external” frame, its thin construction integrates it flatly with the pack walls so that the frame 12 and the material making up the inner surface 66 present, together, a fairly uniform surface that presses against the wearer's back. It may be possible to use the same frame arrangement as an “internal” frame as well, although that embodiment has not yet been created in prototype form.

The foregoing description is not to be read in a limiting sense. What is considered to be the spirit and scope of the invention is defined in the patent claim or claims that follow, the interpretation of which is to be made in accordance with established doctrines of claim interpretation. 

1. A backpack having a forked frame with thin but curved flat members that are shaped to conform to and press against the curvature of a wearer's back, the flat members being torsionally flexible relative to each other to accommodate weight shifts in the load carried by the backpack.
 2. The backpack of claim 1, wherein the flat members are connected together by a handle portion of the frame, the handle portion and the flat members being formed from a single piece of material.
 3. The backpack of claim 1, wherein the flat members have lower portions that flare outwardly with respect to portions of the flat members that are connected to the handle portion.
 4. The backpack of claim 2, including a scapular pad connected to the flat members near the handle portion and a pair of lumbar pads connected, one each, to the outwardly flared portion of the flat members.
 5. The backpack of claim 3, including a scapular pad connected to the flat members near the handle portion and a pair of lumbar pads connected, one each, to the outwardly flared portion of the flat members.
 6. The backpack of claim 2, wherein the frame is made of carbon fiber.
 7. The backpack of claim 1, wherein the frame is external of the backpack but substantially integrated with the surface of a packsack portion of the backpack that rides on the wearer's back, so that the frame and packsack portion together press against the wearer's back, the curvature of the curved flat members causing the surface of the packsack portion to likewise conform to the curvature of the wearer's back.
 8. The backpack of claim 1, including at least one shoulder strap having an elastic section that permits the strap to elastically stretch when the backpack is worn, the amount of elastic stretch being limited by a separate strap that has opposite ends connected to the shoulder strap outside and on opposite sides of the elastic section, the length of the separate strap being greater than the length of the elastic section when it is in a non-stretched condition.
 9. A backpack having a forked frame with thin but flat members that are connected together by a handle portion, the flat members and handle portion being integrally formed from a single piece of material, wherein the frame is also substantially integrated with the surface of a packsack portion of the backpack so that the frame and packsack together press against the wearer's back, and wherein the handle portion extends above the packsack in a way so as to provide a carrying handle. 